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I. D. SMEAD.

. UNDERFEED FURNACE.

No. 599,021. Patented Feb. 15, 1898.

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I. D. SMEAD.

UNDERFEED FURNACE. y No; 599,021. I Patented Feb. 1-5, 1898.

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ISAAC D. SMEAD, OF TOLEDO, OHIO, ASSIGNOR TO THE SMEAD FURNACE AND FOUNDRY COMPANY, OF SAME PLACE.

UNDERFEED FURNACE.

SPECIFICATION forming part of Letters Patent No. 599,021, dated February 15, 1898.

Application filed June 28 1897. Serial No. 642,705. (No model.)

To azz whom it may concern:

Be it known that I, ISAAC D. SMEAD, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Underfeed Furnaces, of which the following is a specification.

This invention relates to furnaces of that class denominated underfeed furnaces, to be used for warming buildings; and the invention consists in the novel construction of the devices or means used for feeding the coal from underneath, as hereinafter more fully described.

Figure 1 is a central longitudinal vertical section. Fig. 2 is a transverse vertical section on the line 00 so of Fig. 1, and Fig. 3 is a horizontal transverse section on the line y y of Fig. 1.

The object of my present invention is to produce a'furnace of great heating capacity in which the fire is produced at the two sides of a long fire-box and in which the fuel is fed in from below.

The construction of the furnace proper is fully described in another application filed simultaneously herewith, and will not therefore be described herein except so far as may be necessary to a clear understanding of the construction and operation of the underfeed devices and the parts cooperating therewith.

Various attempts have heretofore been made by myself and others to construct afurnace with an underfeed for use in warming buildings; but owing to certain difficulties such attempts have generally been unsuccessful, so that there is not on the market at the present timeany successful furnace of this class. After long and costly experiments I have succeeded in producing an underfeed furnace which works successfully and which is constructed as follows:

I make the body A of the furnace of a series of cast-iron plates having both interior and exterior radial flanges B G, with a continuous smoke-flue G at the top, said flue being connected to the fire-chamber by a continuous narrow throat or slot, as clearly shown in Fig. 2.

As shown in Fig. 3, the fire-box or body of the furnace is oblong, and by using more or less sections or plates it may be made of any length desired, this construction, together with the drums in rear of the body and other features, being fully described in my application hereinbefore referred to.

Instead of the ordinary grate I locate at each side a narrow grate composed of two parts, one part E being arranged in a horizontal plane and the part F next to the side walls being inclined, as shown in Fig. 2.

Between the grates at the center I place a concave plate O to form a chute for conveying the coal, this plate gradually increasing in width from its front to its rear end, as shown in Fig. 3, the side grates E being correspondingly wider at their front and narrower at their rear ends, as is also shown in Fig. 3. The concavity of the plate 0 is regularly decreased from its front to its rear end, so that at its rear end it comes level with the side grates E, thus forming a long slightly-- inclined chute, which grows continuously wider and more shallow and flat from its front toits rear end, as shown in Figs. 1 and 3. At its front end this chute O is connected to a horizontal rectangular box 6, which has an opening in its upper side and over which I locate a hopper or magazine H, the upper portion of which is curved outward and extends through the front plate T, which is set some distance from the front of the fire-box, as shown in Figs. 1 and 3. This hopper is increasedin diameter from where it curves downward to where it connects with the box e to enable the coal to feed down freely and without clogging. It is provided at its upper end with adoor d, and at its top it is connected by a pipe I to the front end of the smoke-flue G, as shown in Fig. 1, by which an inward draft is created when the door is opened to draw inward any coal dust or gas that may be present. 4

In the boxe I place a follower J, which consists of a vertical plate and a transverse top plate t of the full width of the box 6, with narrow side'plates a and an outwardly-projecting'rack-bar K, all as shown in Fig. 3. This follower J is from two-thirds to three fourths of the height of the box e, there being a cross-plate 0' at the front of the box e, which reaches down to the top of the follower, and a narrower cross-plate b at the rear side of the box e, this plate 6 being of such a width as to leave a small space between its lower edge and the top of the follower, as shown in Fig. 3.

To the furnace-front I pivot a segmental rack D, the teeth of which engage with the teeth of the follower rack-bar K, which is supported by a loose roller 25, as shown. The segmental rack D is formed with a vertical arm 0, which is made hollow to receive the operating-lever L, which can be detached and set aside when not in use.

By this construction I am enabled to produce an underfeed which, as shown by experiment, works perfectly and with ease. The hopper increasing in diameter from the top downward permits the coal to feed down without clogging, while the peculiar form of the chute, growing constantly wider and shallower from front to rear, enables the coal to be shoved in without clogging and with much greater ease. The space left between the top of the follower and the cut-off or front crossbar I) also serves to prevent the follower from being stopped by the coal, as it would be if said cross-bar extended down flush with the top of the follower.

In practice I prefer to perforate the rear portion of the chute, as shown in Fig. 3, for the purpose of admitting air at that point to mingle with and consume the gases given off by the burning coal, more especially as the grates E, being narrower at the rear, will not admit as much air as at the front, where they are wider; but I wish it distinctly understood that my invention is not limited to a perforated chute, as it is obvious that it may be made without the perforations, and so far as the feeding is concerned will operate equally well. So, too, while I prefer to use the inclined side grates, because they tendto keep the ashes away from the side walls of the firebox and also admit air at a higher point at the sides, still it is obvious that the feed apparatus may be used without the inclined grates by simply making the horizontal grates E wider, so as to extend out to the side walls.

It will be observed that the hopper is located between the furnace-front T and the front end of the furnace-body or fire-box, thereby hiding everything from View except the rack-bar and the segment which operates the same, thus giving to the whole a neat appearance, differing but little in appearance from the Smead furnaces heretofore made and used.

While I prefer to use my improved underfeed with the style of furnace shown, I do not limit myself in that respect, as it is obvious that this underfeed maybe used with furnaces having their bodies or fire-boxes made dilferently from this; but whatever the style of furnace maybe I prefer to use the long narrow grates at the sides as giving the best results.

Having thus fully described my invention, what I claim is 1. In an underfeed furnace, a central concave coal-chute O of continuously-increasing width and decreasing depth from its front to its rear end, with perforations in its rear portion, substantially as shown and described.

2. The combination in a furnace, of the inclined central coal-chute C of continuouslyincreasing width from its front to its rear end, and grates at the sides thereof of continuously-decreasing width from front to rear, substantially as described.

The combination in a furnace, of the central inclined coal-chute C, the front extension or box e provided with the cross bars or plates Z), c, the follower J provided with the rack-bar it, supported by the antifrictionroller 75, and the segmental rack D with lever L, all constructed and arranged to operate substantially as shown and described.

4. The combination in an underfeed fun nace, of the upwardly-inclined central coalchute C with its front extension c and follower J, and the hopper II having its upper end opening outward through the furnacefront and its lower end opening into the extension e of chute C, all constructed and arranged to operate substantially as shown and described.

5. In combination with the furnace body or chamber A having a heat and smoke flue G along its top and communicating therewith, the hopper H, and pipe I connecting the hopper with said heat-line, said hopper and pipe being located between the furnace body or chamber and the furnace-front, substantially as shown and described.

In witness whereof I hereunto set my hand in the presence of two witnesses.

ISAAC D. SMEAD.

WVitnesses:

L. A. WILLOUGHBY, ANTHONY KUEFER. 

